1. Field of the Invention
The present invention relates to the field bone fixation. In particular, embodiments relate to spinal fixation systems and methods of use thereof.
2. Description of the Related Art
Spinal fusion is a surgical technique in which one or more spinal vertebrae are joined together such that relative motion no longer occurs between them. This technique is commonly used as treatment for fractured vertebrae, spinal deformities, spinal instability, and cervical disc herniations. In many cases, spinal fusion includes bone grafting followed by spinal immobilization. The bone grafting procedure generally includes placing pieces of bone (or bone substitute) between the vertebrae to be fused. Bone grafting, however, does not immediately fuse the vertebrae; instead, bone grafting stimulates the patient's body to grow new bone between the vertebrae. After bone grafting, the vertebrae are held fixed together, or immobilized, in order to allow growth of the new bone.
Various spinal fixation systems and methods are used to immobilize vertebrae after bone grafting. Many of these systems include at least one deformable rod for coupling portions of bone on either side of the vertebrae to be immobilized. The rod is often contoured by hand to fit the anatomy of the patient at the time of surgery. Extensive contouring of the rod during surgery, however, may significantly increase the operating time of the procedure and thus, increase the risk of serious postoperative complications. Furthermore, hand contouring of the rod is often an imprecise technique.
Other systems often include at least two rods having a distal and proximal end. The respective proximal ends of the rods are coupled by a locking mechanism and the respective distal ends are coupled to portions of bone on either side of the vertebrae to be immobilized. The locking mechanisms used in many of these systems require multiple fasteners and often limit the range of relative angulation between the rods. As such, the surgical procedure becomes more complicated and the spinal fixation system becomes less adaptable to the anatomy of the patient. Furthermore, the joint formed by the locking mechanism and the coupled proximal ends of the rods are often relatively bulky and may inflict additional postoperative injury and/or pain on the patient.
In view of these and other concerns, a spinal fixation system that is adaptable to the anatomy of a patient and easily implanted during surgery may be desired.